Hiya all,

Im in the market to do some turbo upgrade work, but there is just so much information around the place (ie on these forums), and Im a bit lost on what way I should be going.

First of all, Im a 'cheapie', so if I can find something cheaper than usual (ie, read Ebay or the like!!) I usually buy it. Thats how I've been able to upgrade my CBR900RR Fireblade (spent $8k, but saved $4k).

Now, Im looking to get my automatic Stagea RB25DET up from 141kw at the 4 wheels, to around 180kw plus. It'll be run via an Apexi SAFC-II, with full 3inch exhaust, a Z32 AFM, larger fuel pump, and either bigger injectors if possible or more pressure thru the fuel rail, as per SK's suggestion.

What should I be doing turbo-wise? I wouldnt mind buying a brand new Garrett turbo in lieu of hi-flowing my standard turbo, but I really arnt too sure on the following: what models bolt straight on with no modifications to flanges or housings, what models have the best response, what models have the most lag, what models would get me that extra 40 - 50 four wheel KW, etc etc.

Currently the standard Stagea turbo spools up from around 2400rpm and I'd like to keep as close to that as possible - I have no real need to be rpm'ing thru the redline.

To anyone reading this - do you have some suggestions, ie turbo types and model numbers, that might do the trick (not just info for me, but for all of you Stagea owners out there).

Cheers to you all, and you are welcome to say 'search the site' I got no probs with that, but really want to pick your brains and see what YOU think.

And a big thank you to you for reading this.....

Brendan

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I am using a GCG ball bearing high flow of an RB25DET turbo for my power target of 200 4wkw. Should do it easily at around 1 bar.

I don't want it hitting full boost at 2,400 rpm though. That's too low an RPM and the standard turbo hits boost on the freeway with just a slight squeeze of the throttle, that unlocks the torque converter and it gazzles gas. Around 2,600-2,700 rpm will be just fine, that way I can hold a steady 110kph without hiiting 0.5 bar every time I tickle the throttle.

cheers

Thanks SK,

Im keeping the GCG in mind, but they are quite expensive arnt they?

Tell you the truth, I'd like to buy something off ebay; you can find new Garrett turbos there quite often, and they dont break the bank (ie under a grand).

Ive read the thread about RB25 dyno results, and there are a few turbos mentioned, but not too much info about how these upgraded snail's come on boost, etc etc.

PPL's, please feel free to add your thoughts to this thread (keeping in mind the Stagea is a heavy wagon)

Brendan B)

I think the GCG would be best suited, but apart from that then maybe the 2830 or 2835 size. The 30 may run out of puff but you'd have really strong mid range.

I'd keep away from the no name turbo's. Almost all would be sleeve bearings and you really don't kow what your getting. Stick with a true Garrett/GCG I say.

J

Thankx Jay95R33,

Good info mate, cheers for that.

On that point, what do people know about the XS power T03 Turbo charger (Rated at 325 HP), with .42 A/R Compressor, .48 A/R Turbine, and bush bearings (not ball bearings).

No good for an RB25DET?

If it doesn't have balls, it doesn't go any where near one of my engines.

cheers

Sounds good!!

Yay, done a little more research into the turbo query.... just wondering why I should send in my standard turbo to GCG to have the hiflow work done for $1950, when Nengun currently sell HKS 2835 pro s for ~$2500...

Going to have to have a chat to our local Adelaide turbo shop (A.T.S.) and make a plan of attack with them, I guess. As it is I wont be doing this work for a while yet, but just doing the research part of the build-up at the moment.

Brendan

The turbines that i would consider are

HKS 2835
Trust T518Z (or 517z)
HKS GTRS
Garret GT35R

Thanks AC,

I'll see what I can find out about these brands youve mentioned.

Maybe a HKS from Nengun might be the way to go, just got to save up that elusive 2k plus customs fee!

Would rather a brand newwy for that sort of money, rather than hiflowing the standard old turbo.

BWilkeson B)

Because;
1. The standard turbo (after being high flowed) bolts straight back on. No mods required, no extra nuts and bolts, no new fittings, no fiddling with water and oil connections, no new inlet piping etc etc.

2. It is never going to be defected for having the standard turbo on it.

3. You won't get the same response out of a 2835 pros as you will out of a GCG Ball Bearing high flow

4. The delivered price is $2,593.77 plus Import Duty 10% and GST 10% total = $3,138. Sometimes you don't get caught and sometimes you do.

cheers

Yup, was keeping that import duty figure in the back of my mind - as you say sometimes you get done for it, other times you dont. (example, my $2000 Keihin flatslide carburettors for the Fireblade came thru no worries no charges, my Galfer wave rotors - which I fitted up on Friday night; bloody awesome! - came thru no worries no charges, but got slugged $80 for a $251 steering damper!!)

So, the HKS 2835 is more laggy than a hiflow? Intresting..... Considering GCG have got back to me and said 220kw is easily acheiveable with their hiflow with both ends ball bearing. Hmm.....

Yah, I was going to keep the standard turbo (if I end up going aftermarket) just in case of the defect situation down here in Adelaide - Im keeping pretty much everything I replace on the Stagea.

Thanks for your information SK, AC and Jay.

Out of curiosity, the 2835 HKS, comes with 0.68 or 0.87 T3 flange, and either 80mm or 100mm... what would work best, keeping in mind I want best response and not top end power (ie under SK's stated 200 4wheek kw mark).

Cheers all,
Brendan

Hi all (again!!)

Quick question, maybe you might be able to help SK seeing we've mentioned the larger injectors etc in threads before.

My power output that Id like from the Stagea is fairly mild, say aroun 180 - 200 kw at the four wheels.

My injectors are currently at 76% duty cycle with 141.3kw at the treads.... would I be better off buying a Sard rising rate fuel pressure regulator, rather than bigger 550cc injectors?

Im thinking Id probably be better off doing the fuel regulator, and a Bosch 040 fuel pump. Ive already got myself a Z32 Air Flow Meter, and would like to get the fueling sorted out before I do some turbo work; most likely hiflow, due to $$ constraints - ie Id rather put $2k into the Stagea and $1k into the Fireblade (as I need a new rear suspension unit, either Ohlins or HyperPro), rather than $3k soley onto the Stagea

How does that sound to you fellow Stagea & RB25DET owners? I value your opinions! Fact is I know f-all about turbo cars.

Brendan

Hi Brendan, you can get a bolt on Nismo adjustable fuel pressure regulator from Nengun for ~$150. Just unbolt the standard (non adjustable) FPR and replace it with the Nismo adjustable FPR.

Note that this is a linear rate (not rising rate) FPR, ie; it maintains the same (but adjustable) fuel pressure above boost, whereas rising rate means the pressure above boost increases. I am not a fan of rising rate FPR's, they make tuning with piggy backs very difficult. They are OK for full replacement ECUs' or on cars that weren't turbocharged originally.

I will repeat my usual word of warning, I don't like increasing the fuel pressure too much above standard without upgrading the fuel hoses and clamps. The standard hoses and clamps are designed for a base pressure of 36-38 psi, plus boost of 6 psi, making 42-44 psi in total. Increase the fuel pressure to say 45 psi then add 15 psi of boost and you have 60 psi in the fuel hoses. That's a big (~40%) increase in the load on the hoses and clamps.

cheers

Thanks SK for the words of advice (and warning!!)
Thats excellent information, again my thanks to you.

So, either I beef up the injectors and add an 040 Bosch fuel pump, or I grab a standard Nismo fuel regulator and beef up all the fuel lines and still add the bigger fuel pump.

How much usually would you spend on upgrading the fuel lines? Isnt this what youve got planned for your Stagea